Construction for preventing shift of sheath

ABSTRACT

A contact element includes a clamped portion connected on a shielding net folded back on a sheath after being exposed by removing an end portion of the sheath of a shield wire, and a folded portion formed to extend the clamped portion, the folded portion being folded to an inside of the clamped portion, and inserted between the shielding net and an inner insulator so that the sheath and the shielding net are nipped by the clamped portion and the folded portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a construction for preventing a shift of asheath at a connecting portion between a metal shell and shielding netof a shield connector.

2. Background

In a shield connector, a conductive cover (hereinafter, referred to ametal shell), for shielding an inner conductor from an outside electricfield, and a shielding net (hereinafter, referred to a net) of a shieldwire are electrically connected. FIG. 5 is a cross-sectional viewillustrating the connection between the metal shell and the net. FIG. 6is an enlarged view of a portion VI in FIG. 5.

A connector 1 includes a cylindrical outer housing 3 and a cylindricalinner housing 7 with a terminal receiving chamber 5 integrally formedwithin the outer housing 3. A shell insertion groove 11 for receiving ametal shell 9 is formed between the outer housing 3 and the innerhousing 7.

On the other hand, a terminal 17 is connected to a conductor 15a of aninsulated core 15 of a shield wire 13 by clamping. The terminal 17 has aflange portion 21 which is engaged with an elastic terminal retainingpiece 19 formed within the terminal receiving chamber 5. An end portionof a sheath (outer insulating cover) 23 of the shield wire 13 is removedto expose an end portion of a net 25. The end portion of the net 25 isfolded back on the sheath 23. On the folded portion of the net 25, aconnecting portion 9a of the metal shell 9 is press-fitted to the net 25by clamping in the direction of arrow a (see FIG. 6). Thus, the net 25and the metal shell 9 are electrically connected to each other.

The terminal 17 connected to the shield wire 13 by clamping, is insertedinto the terminal receiving chamber 5, thereby the flange portion 21 isengaged with the terminal retaining piece 19 to prevent a withdrawal ofthe terminal 17. At the same time, the metal shell 9 is inserted intothe shell insertion groove 11. A rubber plug 27 is attached on theshielding wire 13 at a position rearwardly of the outer housing 3 forpreventing water and dust from entering. The rubber plug 27 is heldwithin the outer housing 3 by a rear holder 29.

Thus, the connector 1 of the above described construction can prevent anelectro-magnetic wave fault by the metal shell 9, which is connected tothe net 25, covering the inner housing 7 and shielding the innerconductor from the outer electric field.

However, in the conventional metal shell and net arrangement, since theconnecting portion 9a of the metal shell 9 is press-fitted to the net 25by clamping the connecting portion 9a from the outside thereof aftercovering the net 25, a force for clamping the connecting portion 9a isabsorbed by a deformation of the sheath 23 or the insulated core 15,therefore, it has caused a failure of clamping. As a result, inparticular, a shift of the sheath by a tension caused due to the wiringhas occured. Further, the shielding performance is lowered by aninsufficient contact between the metal shell 9 and the net 25 due to theshift of the sheath. On the other hand, in the conventional example, anadhesive is applied to the clamped portion for preventing the shift ofthe sheath, however, there is encountered a drawback that the efficiencyof the operation is low.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above problems, andan object of the invention is to provide an improved construction forpreventing the shift of the sheath, which can prevent the shift of thesheath at the connecting portion between the metal shell and the net,and to prevent a lowering of the shielding performance and to improvethe efficiency of the operation.

In order to solve the problems described above, according to theinvention, there is provided a construction for preventing the shift ofthe sheath of a shield wire which includes an outer housing; an innerhousing including a terminal receiving chamber for receiving a terminal,formed within the outer housing; a shell insertion groove formed betweenthe outer housing and the inner housing; a metal shell inserted into theshell insertion groove, the metal shell rearwardly extended from theshell insertion groove; and, a contact element including a contactportion connected to the metal shell, a clamped portion connected on ashielding net folded back on the sheath after being exposed by removingan end portion of the sheath of the shield wire, and a folded portionformed to extend the clamped portion, the folded portion being folded toan inside of the clamped portion, and inserted between the shielding netand an inner insulator so that the sheath and the shielding net arenipped by the clamped portion and the folded portion.

The shielding net and the sheath are nipped by the clamped portion andthe folded portion as the clamped portion of the contact element isclamped. As a result, a force for clamping is not absorbed by adeformation of an insulated core and the like, and acts as a force fornipping the shielding net and the sheath effectively. Therefore, thesheath and the contact element are firmly secured to prevent the shiftof the sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a construction for preventing ashift of a sheath;

FIG. 2 is an enlarged view illustrating a contact element used for theconstruction for preventing the shift of the sheath of the invention;

FIG. 3 is a partially enlarged view illustrating a portion III indicatedin FIG. 1;

FIG. 4 is a cross-sectional view of a contact element used for aconstruction for preventing a shift of a sheath according to anotherembodiment of the invention;

FIG. 5 is a cross-sectional view illustrating the connection between themetal shell and the net of the conventional example; and

FIG. 6 is an enlarged view illustrating a portion VI indicated in FIG.5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings, a construction for preventing a shift ofa sheath according to the preferred embodiment of the invention will bedescribed in detail hereinafter.

FIG. 1 is a cross-sectional view of a construction for preventing ashift of a sheath of the invention, FIG. 2 is an enlarged viewillustrating a contact element used for the construction for preventingthe shift of the sheath, FIG. 3 is a partially enlarged viewillustrating a portion III indicated in FIG. 1.

A connector 31 includes a cylindrical outer housing 33 and a cylindricalinner housing 37 with a terminal receiving chamber 35 integrally formedwithin the outer housing 33. A shell insertion groove 39 is formedbetween the outer housing 33 and the inner housing 37. A metalcylindrical shell 41 is inserted into the shell insertion groove 39 soas to contact the outer circumferential surface of the inner housing 37.A large diameter portion 41a is formed on a rear portion of the metalshell 41 to extend from a rear end of the inner housing 37 to the outerhousing 33.

An elastic terminal retaining piece 43 is formed in the terminalreceiving chamber 35 of the inner housing 37, the terminal retainingpiece 43 is engaged with a round terminal which is describedhereinafter. A small diameter portion 45 is formed at the rear end ofthe inner housing 37, therefore, an insertion gap 47 is provided betweenthe metal shell 41 and the small diameter portion 45.

On the other hand, a terminal 53 is press-fitted to a conductor 51a ofan insulated core 51 of a shield wire 49. The terminal 53 has a flangeportion 55 which engages the terminal retaining piece 43 of the terminalreceiving chamber 35. When the terminal 53 is inserted into the terminalreceiving chamber 35, the flange portion 55 is abutted against a frontwall 35a of the terminal receiving chamber 35, at the same time, a rearsurface of the flange portion 55 is engaged by the terminal retainingpiece 43. That is, the flange portion 55 is held by the front wall 35aand the terminal retaining piece 43 to prevent the withdrawal of theterminal 53 while a rotation of the terminal 53 is allowed.

An end portion of a sheath 57 of the shield wire 49 is removed to exposean end portion of a net 59. The end portion of a net 59 is folded backon the sheath 57. A cylindrical contact element 61 is positioned overthe folded portion of the net 59. As shown in FIG. 2, a clamped portion62 in a small diameter is formed on one end of the contact element 61 toconnect the net 59 by clamping after the clamped portion 62 is put overthe net 59. A contact portion 63 in a large diameter is formed on theother end of the contact element 61. The contact portion 63 is insertedinto the insertion gap 47, thereby an outer circumferential surface ofthe contact portion 63 intimately contacts the inner circumferentialsurface of the metal shell 41. The contact element 61 has a plurality offolded portion 65 (in this embodiment, four folded portions), which canbe provided. For example, the folded portions 65 are formed by cutting apart of the contact portion 63 and folding to an inside of the clampedportion 62.

A rubber plug 67 is attached on the shield wire 49 at a positionrearwardly of the outer housing 33 for preventing water and dust fromentering. The rubber plug 67 is held within the outer housing 33 by arear holder 69.

In order to assemble the construction for preventing the shift of thesheath, as shown in FIG. 3, the sheath 57 at the end of the shield wire49 is removed, the exposed end portion of the net 59 is folded back onthe sheath 57, and the clamped portion 62 of the contact element 61 isattached to the net 59 folded back on the sheath 57. At this time, thefolded portion 65 is inserted between the net 59 and the insulated core(inner insulator) 51. That is, the portion of the net 59 folded back onthe sheath 57 is nipped by the clamped portion 62 and the folded portion65. Under this condition, the net 59 and the sheath 57 are press-fittedbetween the clamped portion 62 and the folded portion 65 by clamping theclamped portion 62 in the direction of arrow b (see FIG. 3).

Sequentially, the terminal 53 connected to the shield wire 49 byclamping is inserted into the housing with the metal shell 41 insertedinto the insertion groove 39, at the same time, the flange portion 55 ofthe terminal 53 is engaged with the terminal retaining piece 43.

Finally, the rubber plug 67 is attached to a predetermined position inthe outer housing 33, further, the rear holder 69 for holding the rubberplug 67 is mounted. Thus, the assembly is completed.

In the arrangement, thus assembled, for preventing the shift of thesheath, once the clamped portion 62 of the contact element 61 areclamped, the net 59 and the sheath 57 are nipped by the clamped portion62 and the folded portion 65, and the force for clamping is not absorbedby a deformation of the inner insulator and like, and acts as a forcefor nipping the net 59 and the sheath 57 effectively. Therefore, thesheath 57 and contact element 61 are firmly secured to prevent the shiftof the sheath 57.

As described above, according to the construction for preventing theshift of the sheath, the shift of the sheath does not occur because thesheath 57 is firmly nipped by the clamped portion 62 and the foldedportion 65 so that the folded portion 65 is formed to extend the clampedportion 62 of the contact element 61, and the clamped portion 62 isclamped after inserting the folded portion 65 between the net 59 and theinner insulator 51. As a result, an insufficient contact between themetal shell 41 and net 59 is avoided and the decrease of the shieldingperformance is prevented. Further, an adhesive for preventing the shiftof the sheath is no longer necessary since the clamped portion isstrengthened, which can simplify the assembling work of the wire.

Another embodiment of a contact element used for an arrangement forpreventing the shift of the sheath according to the invention will bedescribed. FIG. 4 is a cross-sectional view of a contact element usedfor a construction for preventing the shift of the sheath according toanother embodiment.

In this embodiment, at one end of a cylindrical contact element 70, acontact portion 73 in a large diameter is formed to intimately contactthe inner circumferential surface of the large diameter portion 41a ofthe metal shell 41. A clamped portion 75 in a small diameter is formedon the other end of the contact element 70, and a folded portion 77 isformed by folding an end portion of the clamped portion 75 into theinside of the clamped portion 75 in cylindrical.

In order to assemble the contact element 70, the sheath 57 on the end ofthe shield wire 49 is removed (refer to FIG. 3), the exposed end portionof the net 59 is folded over the sheath 57, and then the contact element70 is inserted from a side of the contact portion 73 into the shieldwire 49, and the folded portion 77 is inserted between the net and theinner insulator. Thus, the portion of the net 59, which is folded backon the sheath 57 so as to nip the sheath, is further nipped from theoutside by the clamped portion 75 and the folded portion 77. Under thisstate, the net 59 and the sheath 57 is press-fitted between the clampedportion 75 and the folded portion 77 by clamping the clamped portion 75.

As the contact element 61 described above, in the contact element 70,the sheath 57 is nipped by the clamped portion 75 and the folded portion77 as the clamped portion 75 is clamped. Therefore, it is possible toensure a strength of the folded portion 77 largely and strengthen thenipping force between the clamped portion 75 and the folded portion 77,because not only the force for clamping the clamped portion 75 is notabsorbed by a deformation of the inner insulator 51 and the like, butalso the folded portion 77 is folded as it is in the cylindrical shape.

In the embodiment described above, although the contact element 61 andthe metal shell 41 are provided separately, the clamped portion 62 or 75and the folded portion 65 or 77 may be integrally formed with the metalshell 41.

It is further understood by those skilled in the art that the foregoingdescription is a preferred embodiment of the disclosed device and thatvarious changes and modifications may be made without departing from thespirit and scope of the invention.

What is claimed is:
 1. A construction for preventing a shift of sheathof a shield wire, said construction comprising:an outer housing; aninner housing including a terminal receiving chamber for receiving aterminal, formed within said outer housing; a shell insertion grooveformed between said outer housing and said inner housing; a metal shellinserted into said shell insertion groove, said metal shell rearwardlyextended from said shell insertion groove; and a contact element,including:a contact portion connected to said metal shell; a clampedportion connected on a shielding net folded back on the sheath afterbeing exposed by removing an end portion of the sheath of the shieldwire; and a folded portion connected to said clamped portion, saidfolded portion being folded to an inside of said clamped portion, andinserted between the shielding net and an inner insulator so that thesheath and the shielding net are nipped by said clamped portion and saidfolded portion.
 2. The construction of claim 1, wherein said foldedportion is formed by cutting a part of said contact portion.
 3. Theconstruction of claim 1, wherein said contact element has a cylindricalshape.
 4. The construction of claim 1, wherein said contact element hasa cylindrical shape, and wherein said folded portion is formed byfolding an end portion of said clamped portion in cylindrical shape. 5.The construction of claim 1, further comprising a insertion gap formedbetween said inner housing and said metal shell inserted into said shellinsertion groove, wherein said contact element is contacted said metalshell by inserting said contact portion of said contact element intosaid insertion gap.
 6. The construction of claim 1, wherein said contactelement is press-fitted to the shield wire by clamping said clampedportion.
 7. A contact element, comprising:a clamped portion connected ona shielding net folded back on a sheath after being exposed by removingan end portion of the sheath of a shield wire; and a folded portionconnected to said clamped portion, said folded portion being folded toan inside of said clamped portion, and inserted between the shieldingnet and an inner insulator so that the sheath and the shielding net arenipped by said clamped portion and said folded portion.
 8. The contactelement of claim 7, wherein said folded portion is formed by cutting apart of said contact element.
 9. The contact element of claim 7, whereinsaid contact element has a cylindrical shape.
 10. The contact element ofclaim 7, wherein said contact element has a cylindrical shape, andwherein said folded portion is formed by folding an end portion of saidclamped portion in cylindrical shape.
 11. The contact element of claim7, wherein said contact element is press-fitted to the shield wire byclamping said clamped portion.